Slub catcher



W. D. lDE

SLUB CATCHER June 21, 1966 4 Sheets-Sheet 1 Filed July 24, 1963 mum/0r l/l h/7m0/7 [74 M6 By his affameys W. D. lDE

SLUB CATCHER June 21, 1966 Filed July 24, 1963 4 Sheets-Sheet 4 HIHWIIIIIHIIII Hill I IIHIHIEH //7l/6/l/0/ F/ 7 M h/kman O/de By his af/omeys United States Patent "ice 3,256,719 SLUB CATCHER Whitman D. Ide, Laconia, N.I-I.,. assignor to Scott & Williams, Incorporated, Laconia, N.H., a corporation of Massachusetts Filed July 24, 1963, Ser'. No. 297,294 9 Ciaims. (Cl. 66163 This invention pertains to slub catchers for use in circular multi-feed knitting. machines and more particularly to apparatus for detecting and catching yarn' slubs which appear during. feeding of the yarn through apparatus such as rib or plain large diameter body fabric knitting machines.

Low grade yarns of cotton or other fibers sometimes contain what are known as slubs. These are thick, bulky enlargements of the yarn composed of lumps of loose fibers collected on the yarns at the time of spinningv or twisting. Although both spinning and twisting machines are generally equipped with devices known as slub catchers. to detect such defects, one or more slubs may occasionally be accidentally missed. and wound with'the yarn forming the finished package.

When yarns having slubs are used in knitting rib or plain fabric on circular machines of either the' rotary or the stationary needle bed type, there is the possibility thata slub on the yarn will be drawn into the needles of the machine; If the slub is sufliciently large it may damage the needles. If the aperture in a guide or feed finger through which the yarn' passes is small enough to prevent passage of the slub, the yarn will be severed by the needles. The: fabric' thereupon will'drop from the machine. An undetected slub may be expected therefore to result in a defect in the fabric causing considerable expenseand increased cost due toloss of production, unmarketable fabric: and possible machine damage.

Knitting machines are equipped with stop motions designed to stop the machine if yarn breaks. Onthe other hand, the stop motions heretofore available generally will not detect a slub.

Slub catchers are available to the knittingindustry which are combined as units with stop-motion detectors and are designed to be mountedv above the yarn'supply packages on the knitting machines. These units are rather; :bulky,= and, together with'the necessary electrical conductors, seriously interfere with access to the yarn packages. Ready access to the yarn packages is essential when changing or renewing the same;

An additional and significant problem arises in the use of circular body fabric machines having rotating dials and/or overhead yarn supply racks. Suddenstopping of such' large diameter multi-feed machines must ordinarily be avoided because of the weight of the revolving parts. Such machines must normally be brought to a coasting stop in as brief a time interval a possible. Thisis necessary because knitting continues until. the machines have completely decelerated and yarn must be made available to the needles during the entire period ofdeceleration to prevent breaking of the yarn.

A commercially satisfactory solution to the problems recited above is needed. The present invention provides just such a solution. A slub catcher is 50 designed and located in relation to a yarn package, stop-motion slub detector and yarn guide apparatus that when a slub is detected and caught, conventional overhead stop-motion apparatus immediately initiates the usual automatic sequence of events that stop the machine and at the same time causes provision of sufi icient length of free yarn to supply the needles until the machine comesto a complete stop, without the slub having been passed on to the needles.

3,256,7l9 Patented June 21, 1966 While, generally only one yarn and the elements associated therewith will be shown and described, it is to be understood that a similar arrangement can be provided for each yarn on a multi-feed machine.

Those elements of a knitting machine which are not necessary to a comprehensive and workable presentation of theinvention'have been omitted from the drawings in order that the nature of the invention will readily become apparent.

In the drawings FIGURE 1 is a plan view of a multi-feed circular body fabric knitting machine showing the yarn packages, slub catchers, stop-motion slub detectors and yarn guide apparatus used in the invention.

FIGURE 2 is a view in elevation of the multi-feed knitting machine of FIG. 1 showing just two feeds, in order to maintain clarity. Each feed is illustrated as if in normal operation, no slub being present. In addition, the figure illustrates a drive unitconnected to a stop motion slub detector.

FIGURE 3 is a detail view in side elevation of one of the slub catchers used in the invention, showing a slub preventing yarn from moving along the normal path through the slub catcher. The figure also shows in dotted position the slub drawn from the slub catcher and the-yarn thus bypassing the latter.

FIGURE 4 is a view inelevation of the novel slub catcher as seen looking radially outward from the center of the knitting machine.

FIGURE 5 is a view in perspective of one of the novel slub catchers, and detectors and yarn guide apparatus associated therewith, illustrating how, when a slub is caught, the yarn is tightened to actuate the associated yarn guide and stop-motion slub detector, the yarn thereafter assuming a shorter than normal path of traverse.

FIGURE 6 is a view in elevation of the knitting ma chine of FIGURE'Z just after a slub has been caught, and the associated yarn guide and stop-motion slub detector has been actuated by the yarn loop.

FIGURE 7 is a view in elevation of the knitting machine of FIGURE 6 showing after the slub has been disengaged in such manner from the slub catcher how enough yarn can be drawn from the yarn package over the new and short route to the needles until the machine comes to a stop, without the slub being passed onto the needles.

In FIGURE 2 of the drawings the knitting head of a multi-feed circular body fabric knitting machine is indicated generally by the arrow 2. Outside the head are a plurality of pillars 4 which support cross-bars 6 (FIGS. 1, 2 and 7). On the head per se, cylinder needle cams and dial-needle cams are indicated by 43 and 44 respectively.

The conventional central vertical support rod 3 for the yarn is suported on the cross-bars 6 as usual. Just above the cross-bars 6 are the conventional hub 10 and support arms 22 carrying the yarn support bases or supply stands 20 for the yarn packages 18. Still on the central support rod 8, but above the yarn supply stands, is a yarn guide disc 12 having eyes 13 therearound, the yarns passing downwardly through these eyes to the knitting head of the machine. Just above the disc 12 is a hub 14 with outrigger support arms 26 going to the individual novel slub catchers, indicated generally by the arrow 24, of the present invention, and above the slub catcher support hub 14, still on the central rod 8, is a spider 16 with legs 29 radiating therefrom carrying the stop-motion slub detectors shown generally by the arrow 28.

The yarns going downward to the yarn guide disc come from the individual pivoted yarn guides 30 which act as stop-motion slub detector arms or triggers and these are either electrically (as shown by wires 45) or mechanically connected to a trip mechanism or brake 47 to stop the machineif any one of the detector arms is pulled downward to the position shown by the upper right hand yarn guide and detector arm shown in FIGURE 6. Thus if the yarn riding on a detector arm is tensioned by a slub, as hereinafter described, the drive 46 of the machine is cut off and the brake 47 is so applied as to bring it to a coastingstop.

Turning now to the slub catcher 24 itself, this unit has a vertical post 32 adjustably. clamped by a screw 34 to the outrigger support arm 26. At the lower end of the ver tical post is a plate 37 for a yarn guide device or eye 38 which plate and eye are attached to the under side of the slub catcher at the lower end of the vertical post by a screw 36 (see FIG. 3). The yarn 19 coming from the yarn package 18 passes through the eye 38 from below. This is true whichever of the two positions shown in FIG. 3 the yarn occupies as it leaves the upper side of the eye. Above the support arm 26 a pair of blades 40 is carried on the post 32. The blades slope downward toward the center of the machine (see FIGURES 3, 4, 5 and 6). Each blade is adjustably mounted by means of a separate over-sized hole and a screw 42. The facing edges of the blades are preferably substantially parallel to each other and are set to provide an opening or gap 41 just wide enough to permit the yarn to pass freely therethrough but to catch and prevent passage therethrough of any slub that may come along.

When the yarn coming from the yarn package 18 is normally threaded up it will pass through the yarn guide eye 38, between the blades 40, and up to the pivoted yarn guide and stop motion slub detector arm 30.

For clarity of description the portion of the yarn between the slub catcher 24 and the pivoted yarn guide and detector arm or trigger 30 is identified in the drawings by the reference character 21. The portion of the yarn passing downward from the detector arm 30 to the centrally disposed yarn guide device or eye 13 is identified by the reference character 23. From the said eye 13 the yarn pases downward to the usual yarn guide 15 and finally to the needles indicated generally at 17 (see FIG. 2). This arrangement is true whether the machine has only cylinder needles or is a rib machine with dial needles as well. The machine shown in FIGS. 2 and 7 is a rib machine.

Having thus set forth the arrangement of parts of the machine so far as is necessary to ensure understanding of the invention, I shall now describe the operation of the machine.

During knitting the yarn is normally drawn along the path recited above, which is the path shown on the left and right sides of FIG. 2. If a slub 27 comes from the yarn package 18 it will pass through the eye 38 just under the slub catcher outrigger support arm 26 and be caught by the blades 40 of the slub catcher itself. This activity immediately results in abnormal tensioning of the yarn portions 21 and 23 going to and coming from the detector arm or trigger 30, and the said yarn pulls the arm 30 downward to the position shown on the right of FIGURES 5 and 6. This pivotal action of the arm 30 acting through the rest of the stop motion apparatus, including the drive 46 and the brake 47, cuts 01? the current and initiates a coasting of the machine to a stop. The pivotal movement of the detector arm 30 also releases that loop of yarn formed by the portions 21 and 23 thereof which met in contact with the arm 30, so that the loop falls free. It will be noted that up to this moment the yarn has been passing upward for some distance from the slub catcher 24 to the detector arm 30 as shown by the yarn portion 21 and downward again to a position slightly below the slub catcher at the eye 13 as shown by the yarn portion 23. These two yarn portions and part of the portion 19- from the eye 13 to the needles all precede the slub 27 and are on the needle side thereof. The release of the portions 21 and 23 makes it possible for the machine to continue to knit for a short time while it begins to slow down,

by drawing on the yarn portions 21 and 23 until the yarn assumes a shorter path 25 defined by the yarn passing directly from the slub catcher to the eye 13. Thereafter, and in addition, as can be seen from the dotted position of the yarn in FIGURE 3, not only does this change of path of traverse provide considerable yarn which can be knit while the machine slows down but as the portions 21 and 23 are drawn down the slub 27 is easily, and without force, freed from the slub catcher and the portion of yarn 25 is thereafter enabled to move in the direction of the knitting head 2 with no interference until the slub 27 reaches the yarn guide 15 (see FIG. 7). This arrangement creates, in effect, two yarn supplies which together generate a quite adequate quantity of yarn that enables the machine to come to a complete stop before the slub comes up against the yarn guide 15.

An additional path of yarn traverse is provided by the invention. Relative to each other, there is a first and normal longer-than-necessary path that includes the slub catcher 24 and the yarn guide and stop-motion slub detector arm or trigger 30, and a second path substantially shorter than the first, which second path bypasses the two aforesaid elements and is used during the deceleration of the knitting machine. The shift from the longer-thannecessary path to the second and short path results in the generation of a length of free yarn but which generally would be insuflicient were it not for the disengagement.

of the arrested slub from the slub catcher in such a manner that yarn can again be drawn from the yarn package until the slub reaches the yarn guide 15. However, before this can occur the machine has come to a complete stop.

The location and mounting of the various elements used in the invention are important to achievement and workability of the invention. The disclosed system provides means for detecting and catching slubs, actuating stop motions and thereafter ensuring availability of a supply of free yarn which is sufiicient to continue the knitting operation until the machine has completely stopped. Passage of any slub to the needles is positively prevented. Yarn remains unbroken. Damage to the machinery is prevented. Fabric remains in place. To resume knitting by the machine, an attendant has only to pick off any offending slub, reset the yarn guide and detector arm, rethread the slub catcher, pass the yarn over the arm and start the machine.

It is to be understood that the embodiments of this invention as described above and in the claims that follow, are not intended to limit the scope of the invention thereto. Modifications not here suggested, which may occur to those normally skilled in the art are also considered to be within the ambit of the invention.

What is claimed is:

1. A multi-feed circular knitting machine having (a) a knitting head,

(b) a stop motion adapted to bring the machine to a halt, v (c) a yarn supply for each feed, (d) a separate catcher for slubs coming from the yarn supply associated with at least one feed and located above the knitting head, in combination with (e) a slub detector in each feed having a catcher, located above the catcher and remote therefrom, adapted when the catcher engages a slub and thus tensions the yarn to trigger the stop motion and release the yarn from the slub detector,

(f) a yarn guide device for each catcher near the level thereof but laterally separated therefrom and adapted to receive yarn from the associated slub detector,

v there being (g) open end blades on each catcher so disposed in relation to each other as to provide space therebetween suflicient for the yarn to pass to the slub detector and narrow enough to catch a slub, subsequent triggering of the stop motion by the slub detector initiating a change of the angle of traverse of the yarn relative to the catcher and generation of surplus free 'yarn between catcher and yarn guide device for knitting and simultaneously causing the slub to freely slip out from the open ends of the blades and feed toward the needles;

whereby two supplies of yarn are obtained to feed the needle while the machine decelerates, without breaking the yarn and'causing damage to the fabric. 2. A multi-feed circular knitting machine having (a) a stop motion adapted to bring the machine to a halt, (b) a yarn supply for each feed, and (c) a separate catcher in each feed for slubs coming from the yarn supply associated with that feed, in combination with (d) a slub detector in each feed mounted above each catcher and remote therefrom to receive yarn from the catcher, adapted when the catcher engage-s a slub and tensions the yarn to trigger the stop motion and release the yarn from the slub detector, and (e) a yarn guide device for each catcher near the level thereof but laterally separated therefrom adapted to change the angle of traverse of, and receive yarn from the associated slub detector and freely guide the slub away from the catcher;

whereby when a slub is engaged by a catcher those portions of the yarn from the catcher to the detector and from the detector to the guide device are shortened to asingle portion moving directly from adjacent catcher to guide device, thereby supplying slub-free yarn to the knitting operation while the machine is slowing down. 3. A multi-feed circular knitting machine having (a) a stop motion adapted to bring the machine to a halt, (b) a yarn supply for each-feed and machine and open at their lower ends, there being space between the blades sufficient'topass the yarn therethrough and narrow enough'to catch a slub, the elevation of the guide device being such that when the yarn goes direct from the slub unobstructedly catcher to thesaid device the slub slips out the open ends of the blades and can feed toward the needles while the machine slows down.

5. A multi-feed circular body fabric knitting machine 10 having (c) a separate catcher in at least one feed for slubs coming from the yarn supply associated with that feed,

(d) said catchers each being above the knitting head and having two open-end blades with suificient space for the yarn to pass therebetween and narrow enough to catch a slub, in combination with (e) a slub detector above each catcher adapted to rehaving (a) a knitting head,

(b) a stop motion adapted to bring the machine to a halt, and

(c) a yarn package for each feed, in combination with (d) separate means to protect the fabric from dam-age due to slubs from each yarn pack-age comprising (e) a slub catcher mounted above the knitting head,

(f) a slub detector mounted above the slub catcher and adapted to trigger the stop motion and release the yarn from the slub detector when the slub catcher engages a slub and tensions the yarn,

(g) a yarn guide device disposed near the level of but laterally separate from the slub catcher and adapted to receive yarn from the slub detector initially and from adjacent the slub catcher after the slub detector has released the yarn, said catcher comprising two blades sloping downward toward the center of the (a) aknittinghead,

(b) a stop motion,

(c) a yarn package for each feed, and

(d) braking means adapted to bring the machine to a coasting stop after detection of a slub, in combination with (e) separate means'for each yarn package to protect the fabric from-damage due to slubs comprising a slub catcher sloping downward at an angle to the horizontal toward the center of the-machine and mounted above the knitting head, said catcher having two blades with open lower ends with space therebetween sufiicient to pass the yarn and narrow enough to catch -a'slub,

(f) a slub detector coordinated with the stop motion and located above the slub catcher, at an angle in relation therewith, to receive yarn from the space between the blades, said detector being adapted'to trigger the stop motion when the slub catcher engages a slub and thereby tensions the yarn, and

(g) -a centrally disposedguide eye just beneath the slub catcher to ensure that after triggering of the 'stop motion any yarn going direct from adjacent the slub catcher to the yarn guide eye readily-slides out from under the open ends of the bladesand moves toward the needles while the machine slows down.

6. A multi-feed circular body fabricmachinehaving (a) a knitting head,-and

(b) a yarn package for each feed located above the knitting head, said knitting head havingtherein (c) independent needles,

(d) body means in the head to carry the needles, and

(e) yarn guides to deliver yarn from the yarn packages to the needles, there being relative rot-ary'movement between the body means and the guides, and in combin-ationwith' the knitting head (f) a stop motion slub detector for each feed,

(g) braking means adapted to bring the machine to a coastingstop upon detection of a slub,

(h) a separate'slub catcher forat least one feed above the knitting head but below the associated slub detector, said catcher having two blades at an angle to the horizontal facing downward toward the center of the machine, the blades having open lower ends with space therebetween sufficient to pass the yarn and narrow enough to catch a slub, the associated slub detector being adapted to'trigger the stop motion when the slub catcherengages a'slub thereby tensioning the yarn, and

(i) a yarn guide eye disposed near the level of but laterally separate from the slub catcher and adapted to receive yarn from the associated slub detector initially and from adjacent the slub catcher after the associated slub detector has released the yarn, the elevation of the guide eye being such that when the yarn goes direct from adjacent the slub catcher to the said eye the slub easily slips out the open ends of the blades and can feed toward the needles while the machine slows down.

7. A multi-feed circular body fabric machine having (a) a knitting head and (b) a yarn package for each feed located above the knitting head, said knitting head having therein (c) independent needles,

(d) a needle cylinder containing needles and (e) a dial containing needles, and

(f) yarn guides to deliver yarn from the yarn packages to the needles, there being relative rotary movement between the cylinder and dial on the one hand and the yarn guides on the other, and in combination with the knitting head (g) a stop motion slub detector for each feed,

(h) braking means adapted to bring the machine to a coasting stop upon detection of a slub,

(i) a separate slub catcher for each feed above the knitting head but below the associated slub detector, each such catcher having two blades at an angle to the horizontal facing downward toward the center of the machine, the blades having open lower ends with space therebetween suflicient to pass the yarn and narrow enough to catch a slub, the associated slub detector being adapted to trigger the stop motion when the slub catcher engages a slub thereby tensioning the yarn, and

(j) a yarn guide eye dispsoed near the level of but laterally separate from the slub catcher and adapted to receive yarn from the associated slub detector initially and from adjacent the slub catcher after the associated slub detector has released the yarn, the elevation of the yarn guide eye being such that when the yarn goes direct from adjacent the slub catcher to the said eye the slub slips readily out the open ends of the blades and can feed toward the needles while the machine slows down.

8. A multi-feed circular body fabric machine having (a) a knitting head,

(b) a yarn package for each feed located above the knitting head,

(c) independent latch needles in the head,

(d) a stop motion slub detector for each feed and (e) braking means adapted to bring the machine to a coasting stop upon detection of a slub, in combination with (f) a slub catcher for each yarn pack-age located above the knitting head,

(g) said catcher having two blades at an angle and having open ends with space between the blades sufficient to pass the yarn onto the associated slub detector and narrow enough to engage any slub thereby tensioning the yarn, the associated slub detector having .a trigger pivoted to release the yarn when actuated by such tension, and

(h) a disc with a guide eye for each catcher near the level of the latter but centrally located on the machine and laterally separated from the catcher adapted to receive yarn from the associated slub detector until a slub is detected,

(i) the angle of the blades being from the horizontal downward toward the center of the machine and the level of the disc being such that the dropping of the yarn by the pivoting of the trigger both shortens the path of the yarn from adjacent the catcher to the disc and allow-s the slub to easily slip out the open ends of the blades;

whereby there is surplus yarn which has passed the catcher and thereafter yarn following the slub both of which surpluses can feed toward the needles while the machine is slowing down.

9. A multi-feed circular body fabric machine having (a) a knitting head,

(b) a yarn package for each feed located above the knitting head,

(c) cylinder needle cams and dial needle cams in the knitting head,

(d) independent latch needles in the head,

(e) a plurality of pillars extending upwardly past the head,

(f cross-bars above the head supported by the pillars,

(g) a vertical rod at the center of the machine carried by the cross-bars, and

(h) a support for each yarn package, mounted on the central rod but radially spaced therefrom, in combination with (i) a stop motion slub detector for each package having a pivoted trigger,

(j) braking means adapted to bring the machine to a coasting stop upon detection of a slub,

(k) a slub catcher for and just above each yarn package radially spaced from the central rod having two blades facing downward at an angle toward the central rod with space therebetween sufiicient to pass the yarn and narrow enough to engage a slub, the associated slub detector receiving yarn from the downward angled blades and upon engagement of a slub by the catcher adapted to be triggered by the resulting yarn tension and to drop the yarn by pivoting the trigger of the associated slub detector, the lower ends of the blades being open, and l (l) a yarn guide disc on the central rod with guide eyes therein for the yarn, there beingrelative rotation between the cylinder and dial on the one hand, and the disc on the other, the disc being located close to the rod at such level that the dropping of the yarn by the pivoting of the trigger shortens the yarn path to the knitting head thereby supplying surplus slub free yarn usable while the machine coasts to a stop, and also lowering the yarn from the catcher to a position below the open ends of the blade thus readily freeing the slub and allowing the yarn following the slub to move toward the needles as a second source of yarn supply the machine slows down.

References Cited by the Examiner UNITED STATES PATENTS 2,080,903 5/1937 Wachsman 66-163 2,126,348 8/1938 Rosenfeld 28-64 2,190,521 2/1940 Normandeau 66-163 2,215,220 9/1940 Lawson et al 66-163 2,804,761 9/1957 Lebocey 66163 DONALD W. PARKER, Primary Examiner.

P. C. FAW, Assistant Examiner. 

1. A MULTI-FEED CIRCULAR KNITTING MACHING HAVING (A) A KNITTING HEAD, (B) A STOP MOTION ADAPTED TO BRING THE MACHINE TO A HALT, (C) A YARN SUPPLY FOR EACH FEED, (D) A SEPARATE CATCHER FOR SLUBS COMING FROM THE YARN SUPPLY ASSOCIATED WITH AT LEAST ONE FEED AND LOCATED ABOVE THE KNITTING HEAD, IN COMBINATION WITH (E) A SLUB DETECTOR IN EACH FEED HAVING A CATCHER, LOCATED ABOVE THE CATCHER AND REMOTE THEREFROM, ADAPTED WHEN THE CATCHER ENGAGES A SLUB AND THUS TENSIONS THE YARN TO TRIGGER THE STOP MOTION AND RELEASE THE YARN FROM THE SLUB DETECTOR, (F) A YARN GUIDE DEVICE FOR EACH CATCHER NEAR THE LEVEL THEREOF BUT LATERALLY SEPARATED THEREFROM AND ADAPTED TO RECEIVE YARN FROM THE ASSOCIATED SLUB DETECTOR, THERE BEING (G) OPEN END BLADES ON EACH CATCHER SO DISPOSED IN RELATION TO EACH OTHER AS TO PROVIDE SPACE THEREBETWEEN SUFFICIENT FOR THE YARN TO PASS TO THE SLUB DETECTOR 